Phosphorescent Cyclometalated Platinum(II) Enantiomers with Circularly Polarized Luminescence Properties and Their Assembly Behaviors

Abstract

Platinum­(II) complexes as supramolecular luminescent materials have received considerable attention due to their unique planar structures and fascinating photophysical properties. However, the molecular design of platinum­(II) complexes with impressive circularly polarized luminescence properties still remains challenging and rarely explored. Herein, we reported a series of cyclometalated platinum­(II) complexes with benzaldehyde and its derived imine-containing alkynyl ligands to investigate their phosphorescent, chiroptical, and self-assembly behaviors. An isodesmic growth mechanism is found for their temperature-dependent self-assembly process. The chiral sense of the enantiomers can be transferred from the chiral alkynyl ligands to the cyclometalated platinum­(II) dipyridylbenzene N^C^N chromophore and further amplified through supramolecular assembly via intermolecular noncovalent interactions. Notably, distinctive phosphorescent properties and nanostructured morphologies have been found for enantiomers 4R and 4S. Their intriguing self-assembled nanostructures and phosphorescence behaviors are supported by crystal structure determination, 1H NMR, emission, and UV–vis absorption spectroscopy, scanning electron microscopy, and X-ray powder diffraction studies.

A Low‐Temperature‐Resistant Flexible Organic Crystal with Circularly Polarized Luminescence

“…The enantiomer S(R)-BPEMP powders and crystals lack a perfect mirror image CPL spectrum, which might be caused by the existence of aggregate inhomogeneity in the solid samples. [57] This was preliminarily demonstrated by optical images of the aggregated states and the PXRD experiments (Supporting Information, Figure S8).…”

A Low‐Temperature‐Resistant Flexible Organic Crystal with Circularly Polarized Luminescence

“…The enantiomer S(R)-BPEMP powders and crystals lack a perfect mirror image CPL spectrum, which might be caused by the existence of aggregate inhomogeneity in the solid samples. [57] This was preliminarily demonstrated by optical images of the aggregated states and the PXRD experiments (Supporting Information, Figure S8). Recently, organic crystals have been applied as promising anisotropic optical communication medium, especially in nonlinear optical waveguides, chiral information encoded waveguides and heterogeneous waveguides.…”

“…The g PL factors of the two enantiomers are ±6.0×10 −3 from 450 to 700 nm (Figure 3f) and are comparable with the reported CPL intensity of chiral materials at room temperature. The enantiomer S(R)‐BPEMP powders and crystals lack a perfect mirror image CPL spectrum, which might be caused by the existence of aggregate inhomogeneity in the solid samples [57] . This was preliminarily demonstrated by optical images of the aggregated states and the PXRD experiments (Supporting Information, Figure S8).…”

Recyclable photoluminescent composites via incorporating ZnS‐based phosphors into dynamic crosslinking elastomeric matrixes

“…A series of platinum(II) and iridium(III) complexes were systematically designed and precisely synthesized through organic chemical reactions. [15][16][17][18][19] Based on metal-to-ligand, ligand-toligand or intra-ligand charge transfer, [20] corresponding single molecules, oligomers and polymers consisted of platinum(II) and iridium(III) complexes expressed tunable luminescent properties, for example, intense photoluminescence (PL) after external excitation. [21] Apart from organic luminescent materials, inorganic luminophores were obtained by feasible ceramic powder sintering and element doping.…”